Note 7 - Leases (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Jan. 01, 2019
Operating Lease, Right-of-Use Asset	$ 654,000		$ 654,000		$ 730,000
Operating Lease, Payments	77,000	$ 75,000	153,000	$ 149,000
Operating Lease, Cost	$ 110,000	$ 105,000	$ 219,000	$ 208,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset						$ 966,000